In Philippe B scher and colleagues present the

2019-05-15

In , Philippe Büscher and colleagues present the first formal assessment under field conditions of the HAT Sero--SeT rapid diagnostic test and compared its diagnostic accuracy with two other current serological tests: CATT and immune trypanolysis (a very sensitive and specific test that requires laboratory conditions). The study was done in the Bandundu province of DR Congo during an active screening campaign. The investigators noted no significant difference in sensitivity and specificity between the three tests and concluded that the accuracy of HAT Sero--SeT is adequate for HAT serodiagnosis, and thus that the test could be implemented for passive surveillance at peripheral health facilities.
Notably, another rapid diagnostic test developed by the Foundation for Innovative Diagnostics (FIND) in collaboration with SD Bioline has also been developed. The two tests are based on the antibody recognition of the same trypanosome variant surface xanthine oxidase (LiTat 1.3 and LiTat 1.5). Additional efforts are now needed to assess their accuracy and implementation as passive surveillance techniques in different areas in central and west Africa because the variable antigen type recognition pattern of is known to differ geographically and because integration of HAT diagnosis in the primary health-care system is challenging.
Nevertheless, availability of such rapid serodiagnostic tests only partly simplifies the diagnosis of HAT. As for CATT, these rapid diagnostic tests are only serological suspicion tests and parasitological confirmation by central laboratories is needed before treatment can be started. This issue arises because all available serological tests are hindered by insufficient specificity, and fears surround overtreatment with present drugs that are toxic, complex to administer, and require long-term admission to specific treatment centres. In this regard, new oral drugs such as fexinidazole have now entered phase 2 clinical trials and might soon become available. Second-generation rapid diagnostic tests, based on other recombinant proteins or peptides, are also under development as continuous efforts to improve HAT diagnosis. These efforts should be encouraged because they might (alone or in combination) significantly increase the specificity of serological diagnosis and thus simplify treatment decisions. The possibility of being able to treat patients with an oral drug on the basis of a rapid diagnostic test or combination of rapid diagnostic tests would be a giant leap towards the elimination of sleeping sickness: a dream that is now in sight.
A healthy competition exists between several groups to develop HAT rapid diagnostic tests, which should improve quality and provide options in case one test fails to improve diagnostic accuracy. As a neglected tropical disease and with decreasing disease prevalence, progressive commercial disinterest is a possibility for HAT. Thus, reliance on a single rapid diagnostic test for which production could be stopped for economic reasons is dangerous, and could harm the elimination strategy. All the political, financial, and technical ingredients seem to be in place to make HAT elimination a success story. We should not miss this historical opportunity.
Operational research in public health is the investigation of strategies, interventions, instruments, or knowledge that can enhance the quality, coverage, effectiveness, or performance of health systems, health services, or disease control programmes. By showing what works and what does not in various contexts, operational research can provide evidence to help policy makers to adapt health interventions and services for maximum public health benefit.
During a recent workshop organised by the of the European Parliament, experts in the field of operational research concluded that the European Union (EU) should increase its support for this form of research. STOA, which provides independent assessments of scientific and technological options in various sectors including the life sciences, organised the workshop in collaboration with Médecins Sans Frontières, the International Union Against Tuberculosis and Lung Disease, and WHO/TDR.